Like a heat sink. The exposed area of 8' of 3" pipe will be approximately 912^2" (114^2"/ft.). The air under the car won't be as "fresh", or as volumetric as up front, and the heat conduction rate of aluminized steel is less than just aluminum, but it will definitely have an effect. In any case, you have about the effectiveness of 2 CAC's. Not a bad thing, IMO.
In hindsight, you could have designed the system with only the pipe used for cooling. Maybe something for the future. It would really cut a chunk off the cost. Straight sections of extruded/finned aluminum pipe can be had, for not much. Hmmmmmmm.
If you are going through all that trouble for the A-A CAC, you might as well use a A-L CAC. A little extra weight in the trunk won't hurt. But, cost will be a factor.